Like that of his team, Matt Cain's season has been disappointing - something that was highlighted in arguably his worst start of 2013 his last time out.

San Francisco hopes for a strong bounce-back effort Wednesday from Cain as the Giants face their former draft pick Zack Wheeler for the first time.

A day after suffering a 16-inning loss in the series opener, San Francisco fell 10-6 on Tuesday, with Marlon Byrd delivering an eighth-inning grand slam. The defeat was the third straight for the Giants (40-49) and 13th in 15 games.

A year after going 16-5 with a 2.79 ERA, Cain (5-5, 4.85 ERA) has mirrored his team's inconsistency. He's allowed seven or more runs four times this season after entering 2013 with seven such outings lifetime.

The latest of those came Friday in the second-shortest outing of his career, as he surrendered eight runs in 2 1-3 innings of a 10-2 loss to the Los Angeles Dodgers. He walked four after giving up three total walks in his previous three starts.

Cain had posted a 1.82 ERA in his five previous starts.

"He just got out of sync and then couldn't get back on track," manager Bruce Bochy said. "It happens. He's been throwing the ball so well, too, but tonight he was off. There's not a lot you can do as a pitcher when you get out of sync like that."

Cain has gone 3-1 with 2.01 ERA in his last five starts against New York, though he's had little success in getting David Wright out.

Wright, who went 2 for 3 with two runs Tuesday and extended his hitting streak to 10 games, is 11 for 24 with six doubles against Cain.

Wheeler (2-1, 4.29) was drafted sixth overall by San Francisco in 2009 before being sent to the Mets (39-48) in the Carlos Beltran trade in 2011. The right-hander has been shaky in three outings since throwing six scoreless innings in his big league debut, posting a 6.00 ERA in that span.

He surrendered one earned run in five innings of a 12-5 victory at Milwaukee on Friday, yielding seven hits and three walks while throwing 99 pitches.

"I am happy about my outing even though there were some low points," Wheeler said. "You know throwing 20 pitches an inning and only going five, but I battled out there as best I could and got a good result."

He'll look to take advantage of a San Francisco lineup that continues to come up empty in key situations. The Giants have gone 4 for 26 with runners in scoring position in the series' first two games and 12 for 100 during their 2-13 slump.

The Mets, winners of four of five and 14 of 22, will be trying for their first three-game sweep of the season.